1. Field of the Disclosure
The present disclosure relates to an organic light emitting display device.
2. Discussion of the Related Art
Recently, with the advancement of multimedia, the importance of flat panel display (FPD) devices is increasing. Therefore, various FPD devices such as liquid crystal display (LCD) devices, plasma display panel (PDP) devices, and organic light emitting display devices are being used practically. In such FPD devices, the organic light emitting display devices may typically have a fast response time of 1 ms or less. The organic light emitting display devices may also have low power consumption, and may have no limitations in viewing angle because the organic light emitting display devices self-emit light. Accordingly, the organic light emitting display devices are attracting much attention as next generation FPD devices.
General organic light emitting display devices may include a display panel having a plurality of pixels that are respectively formed in a plurality of pixel areas defined by intersections between a plurality of data lines and a plurality of gate lines, and a panel driver that drives the plurality of pixels to emit light.
Each of the pixels of the display panel, as illustrated in FIG. 1, may include a switching transistor ST, a driving transistor DT, a capacitor Cst, and a light emitting element OLED. The switching transistor ST may be turned on by a gate signal GS supplied from a gate line G, and may supply a data voltage Vdata, supplied from a data line D, to the driving transistor DT. The driving transistor DT may be turned on with the data voltage Vdata supplied from the switching transistor ST, and may control a data current Ioled which flows to the light emitting element OLED according to a driving voltage VDD supplied through a power line. The capacitor Cst may be connected between a gate and source of the driving transistor DT, may store a voltage corresponding to the data voltage Vdata supplied to the gate of the driving transistor DT, and may turn on the driving transistor DT with the stored voltage. The light emitting element OLED may be electrically connected between the source of the driving transistor DT and a ground line VSS, and may emit light with the data current Ioled supplied from the driving transistor DT.
Each pixel of the general organic light emitting display device may control a level of the data current Ioled (which flows from the driving voltage VDD terminal to the light emitting element OLED) with a switching time of the driving TFT DT based on the data voltage Vdata to thereby emit light from the light emitting element OLED and display a certain image.
However, in the general organic light emitting display devices, the threshold voltage (Vth) and mobility characteristics of a plurality of the driving transistors DT are different depending on a position of the display panel due to a non-uniformity of a process of manufacturing a thin film transistor (TFT). For this reason, in the general organic light emitting display devices, despite the same data voltage Vdata being applied to the driving transistors DT of the respective pixels, a deviation of currents flowing in the organic light emitting elements (OLEDs) can render the devices unable to realize a uniform image quality.